1. Field of the Invention
The present invention relates generally to bicycle tires and more particularly to a protective liner for a bicycle tire of the pneumatic type to make the tire puncture-proof or at the very least puncture resistant.
2. Description of the Prior Art
Bicycle tires usually have a narrow outer rubber casing having a thin cross-section and an inner, air filled, inner tube. Unfortunately, especially when off road biking, thorns and other sharp objects can easily penetrate the outer rubber casing and puncture the inner tube. Flat tires are a common occurrence for all types of bicycles. Having a flat tire especially on a mountain trail can be a devastating experience leaving the rider stranded without any means of transportation. While many bike riders carry tire repair kits, tools and other devices such as air pumps and sealing materials for repairing flat tires, people often have difficulty in making such repairs especially when the need arises off road or on a mountain trail. In any event, penetration of the outer tire by thorns or other sharp objects resulting in the puncture of the inner tube and a flat is often a very unpleasant and frustrating experience especially if you are in a relatively remote area.
The susceptibility of the pneumatic tire to puncture is inherent in the nature of the elastomeric material that comprise the tire or the tire and the inner tube in the case of a bicycle. When inflated, such elastomeric materials have the well known characteristics of providing both a cushioned ride and also giving greater traction than other materials, while however unfortunately simultaneously having a decreased resistance to sharp objects.
Various proposals have been made as to how this susceptibility to puncture may be avoided with varying degrees of success. Methods which attempt to prevent puncture altogether appear to have been limited to date to so-called tire liners which are attached to the inside of the tire casing or pressurably sandwiched between the casing and an inner tube. In the past such liners have often been expensive and added significantly to the weight of the tire resulting in increased difficulty in propulsion for a cyclist.
Examples of prior art references directed to these problems include: U.S. Pat. No. 520,643 granted on May 29, 1894 to Hoffman relating to a protecting strip adapted to be interposed between the inner and outer tubes of a pneumatic tire with its ends overlapping, said strip consisting of a strip of woven wire fabric and a covering of canvas, the canvas on opposite sides of the strip being united together and to the wire fabric by cement, said cement filling the interstices of the wire fabric. U.S. Pat. No. 600,340 to Thomson & Gibb dated Mar. 8, 1898, in which a metallic band constructed of short lengths of highly tempered steel tape are interlaced or plaited together to form a band of the required width to cover the whole of the puncturable surface of the inner air tube, thereby effectively preventing the puncturing of said tires. U.S. Pat. No. 601,327, granted to Stevenson on Mar. 29, 1898 and relating to an armor or anti-puncture band for pneumatic tires, comprising a series of plates hinged together directly at their meeting ends by metallic fastening devices carried by another series of plates, which are hinged to and overlap the meeting ends of the first named series of plates. U.S. Pat. No. 722,339 granted to Wheeldon on Mar. 10, 1903 relates to an intermediate protecting band adapted to be inserted between the air tube and tread of a pneumatic tire consisting of inner and outer strips of fabric, and a layer of small plain sections of sheet metal fitted together side to side, end to end, and edge to edge between the strips of fabric, and cemented together with the strips of fabric. U.S. Pat. No. 1,177,930 dated Apr. 4, 1916 granted to Henry J. Cohrs relates to a tire protector consisting of a first band of rubber, leather or other flexible material, a second band of rubber , leather or other flexible material and interposed plates of aluminum. Schaefer et al U.S. Pat. No. 1,779,014, relates to a tire insert consisting of several layers or strips of fabric and linen. Hart U.S. Pat. No. 2,205,260 relates to a tire guard consisting of a fabric envelope in which is inserted a flexible metal member. Scimecca U.S. Pat. No. 3,982,577 relates to a tube guard being located when in use between the inner tube and an outer rubber tire casing and comprising a singular annular guard member made entirely from a non-compressible flexible solid plastic material. McGee et al. U.S. Pat. No. 5,785,779 relates to a protective tire liner comprising a puncture resistant strip formed from a plurality of tightly woven fabric layers of Kevlar yarn and since the Kevlar yarn is abrasive a plastic covering layer is spirally wound about the the puncture—resistant flexible yarn to cover at least the side edges thereof. One of the difficulties with fabric and Kevlar, is that a sharp object or thorn will find its way through the weave and penetrate the tube.
Unfortunately, despite the various attempts to provide puncture resistant devices until the present invention, there still existed a need for a practical lightweight and effective device for protecting a bicycle tire, particularly, a mountain bicycle tire from punctures and other damage that cause flats.